Solid-state imaging device, method for driving the same, and camera

Abstract

A solid-state imaging device according to the present invention includes: first vertical transfer units; transfer control units disposed in correspondence with the first vertical transfer units on m columns, and each configured to selectively transfer the signal charges transferred by any of the corresponding first vertical transfer units; and second vertical transfer units each configured to transfer the signal charges transferred by a corresponding one of the transfer control units. Each of the second vertical transfer units is disposed for horizontal transfer electrodes forming a transfer packet of a horizontal transfer unit and has a region in which a transfer width tapers from the corresponding one of the transfer control units toward the horizontal transfer unit. Moreover, each of the second vertical transfer units is provided with a vertical transfer electrode independent of vertical transfer electrodes of the first vertical transfer units and the transfer control units.

1 . A solid-state imaging device comprising:
 photoelectric conversion units disposed in rows and columns and configured to convert light into signal charges;   first vertical transfer units disposed in one-to-one correspondence with the columns and each configured to transfer in a vertical direction the signal charges obtained by said photoelectric conversion units converting the light, said photoelectric conversion units being disposed on a corresponding one of the columns; and   transfer control units disposed in correspondence with said first vertical transfer units on m columns successive in a horizontal direction, where m is an integer greater than or equal to 2, and each configured to selectively transfer the signal charges transferred by any of said corresponding first vertical transfer units on the m columns;   second vertical transfer units disposed in correspondence with said transfer control units and each configured to transfer the signal charges transferred by a corresponding one of said transfer control units; and   a horizontal transfer unit configured to transfer in the horizontal direction the signal charges transferred by said second vertical transfer units,   wherein each of said second vertical transfer units is disposed for two or more horizontal transfer electrodes forming a transfer packet of said horizontal transfer unit and has a region in which a transfer width tapers from said corresponding one of said transfer control units toward said horizontal transfer unit, and   each of said second vertical transfer units is provided with a vertical transfer electrode independent of vertical transfer electrodes of said first vertical transfer units and said transfer control units.   
     
     
         2 . The solid-state imaging device according to  claim 1 ,
 wherein each of said transfer control units includes m of third vertical transfer units disposed in one-to-one correspondence with the m columns and each configured to transfer the signal charges transferred by said vertical transfer unit on a corresponding one of the m columns, and   a distance, in the horizontal direction, between centers of m of said third vertical transfer units disposed adjacent to one another is shorter than a distance, in the horizontal direction, between centers of said first vertical transfer units disposed adjacent to one another.   
     
     
         3 . The solid-state imaging device according to  claim 1 ,
 wherein each of said second vertical transfer units includes:   a fourth vertical transfer unit configured to transfer the signal charges transferred by a corresponding one of said transfer control units and having a region in which a transfer width tapers from said corresponding one of said transfer control units toward said horizontal transfer unit; and   a fifth vertical transfer unit configured to transfer to said horizontal transfer unit the signal charges transferred by said fourth vertical transfer unit and having a constant transfer width, and   vertical transfer electrodes independent of each other are disposed above said fourth vertical transfer unit and said fifth vertical transfer unit.   
     
     
         4 . The solid-state imaging device according to  claim 1 ,
 wherein each of said transfer control units includes m of third vertical transfer units disposed in one-to-one correspondence with the m columns and each configured to transfer the signal charges transferred by said vertical transfer unit on a corresponding one of the m columns,   a sixth vertical transfer unit which is one of said third vertical transfer units on the m columns includes a first vertical transfer electrode to which a same transfer pulse as a pulse applied to any of the vertical transfer electrodes of said first vertical transfer units is applied, and   m−1 of said third vertical transfer units other than said sixth vertical transfer unit included in said third vertical transfer units on the m columns each include a signal charge storage electrode and a transfer blocking electrode which are independent of the vertical transfer electrodes of said first vertical transfer units and said second vertical transfer units.   
     
     
         5 . The solid-state imaging device according to  claim 4 ,
 wherein said sixth vertical transfer unit includes the first vertical transfer electrode only.   
     
     
         6 . The solid-state imaging device according to  claim 5 ,
 wherein a transfer width of an entire region below the first vertical transfer electrode of said sixth vertical transfer unit increases from said corresponding one of said first vertical transfer units toward a corresponding one of said second vertical transfer units.   
     
     
         7 . The solid-state imaging device according to  claim 1 ,
 wherein a maximum transfer width of each of said second vertical transfer units is larger than a width between outermost end portions of said first vertical transfer units disposed on outermost columns of the m columns.   
     
     
         8 . The solid-state imaging device according to  claim 1 ,
 wherein each of said first vertical transfer units includes a first n-type impurities-doped region and a second n-type impurities-doped region,   the first n-type impurities-doped region is formed in each of said first vertical transfer units, each of said transfer control units, each of said transfer control units, and said horizontal transfer unit, and   the second n-type impurities-doped region is formed in each of said first vertical transfer units and each of said transfer control units and is not formed in each of said second vertical transfer units and said horizontal transfer unit.   
     
     
         9 . The solid-state imaging device according to  claim 1 ,
 wherein a potential step is formed in each of said second vertical transfer units so that electric potential on a side of a corresponding one of said transfer control units is shallower than electric potential on a side of said horizontal transfer unit.   
     
     
         10 . The solid-state imaging device according to  claim 9 ,
 wherein a third n-type impurities-doped region is formed in each of said second vertical transfer units on a side of said horizontal transfer unit to form the potential step.   
     
     
         11 . The solid-state imaging device according to  claim 9 ,
 wherein a p-type impurities-doped region is formed in each of said second vertical transfer units on a side of a corresponding one of said transfer control units to form the potential step.   
     
     
         12 . The solid-state imaging device according to  claim 11 ,
 wherein a third n-type impurities-doped region is further formed in each of said second vertical transfer units.   
     
     
         13 . The solid-state imaging device according to  claim 1 ,
 wherein a p-type impurities-doped region is formed in each of said transfer control units.   
     
     
         14 . The solid-state imaging device according to  claim 1 ,
 wherein first vertical transfer electrodes of said first vertical transfer units, said transfer control units, and said second vertical transfer units, and the two or more horizontal transfer electrodes of said horizontal transfer unit are formed of a single layer.   
     
     
         15 . A method for driving a solid-state imaging device, said method comprising
 during a period for which signal charges on one of m columns are horizontally transferred, transferring to a fourth vertical transfer unit the signal charges on other column of the m columns from a transfer control unit corresponding to the other column,   wherein said method is a method for driving the solid-state imaging device according to  claim 3 .   
     
     
         16 . The method for driving the solid-state imaging device according to  claim 15 , said method comprising:
 transferring to the fourth vertical transfer unit the signal charges on a center column, among the m columns, from the transfer control unit corresponding to the center column during a horizontal blanking period; and   during a period for which the signal charges on the center column are transferred, transferring to the fourth vertical transfer unit the signal charges on an outermost column, among the m columns, from the transfer control unit corresponding to the outermost column.   
     
     
         17 . A camera comprising the solid-state imaging device according to  claim 1 .